// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <lib/fidl/coding.h>
#include <stddef.h>

#ifdef __Fuchsia__
#include <lib/zx/eventpair.h>
#include <zircon/syscalls.h>
#endif

#include <memory>

#include <fidl/test/coding/llcpp/fidl.h>
#include <zxtest/zxtest.h>

#include "fidl_coded_types.h"
#include "fidl_structs.h"

namespace fidl {
namespace {

// Some notes:
//
// - All tests of out-of-line bounded allocation overruns need to have
//   another big out-of-line allocation following it. This
//   distinguishes "the buffer is too small" from "the bits on the
//   wire asked for more than the type allowed".

// TODO(kulakowski) Change the tests to check for more specific error
// values, once those are settled.

constexpr zx_handle_t dummy_handle_0 = static_cast<zx_handle_t>(23);
constexpr zx_handle_t dummy_handle_1 = static_cast<zx_handle_t>(24);
constexpr zx_handle_t dummy_handle_2 = static_cast<zx_handle_t>(25);
constexpr zx_handle_t dummy_handle_3 = static_cast<zx_handle_t>(26);
constexpr zx_handle_t dummy_handle_4 = static_cast<zx_handle_t>(27);
constexpr zx_handle_t dummy_handle_5 = static_cast<zx_handle_t>(28);
constexpr zx_handle_t dummy_handle_6 = static_cast<zx_handle_t>(29);
constexpr zx_handle_t dummy_handle_7 = static_cast<zx_handle_t>(30);
constexpr zx_handle_t dummy_handle_8 = static_cast<zx_handle_t>(31);
constexpr zx_handle_t dummy_handle_9 = static_cast<zx_handle_t>(32);
constexpr zx_handle_t dummy_handle_10 = static_cast<zx_handle_t>(33);
constexpr zx_handle_t dummy_handle_11 = static_cast<zx_handle_t>(34);
constexpr zx_handle_t dummy_handle_12 = static_cast<zx_handle_t>(35);
constexpr zx_handle_t dummy_handle_13 = static_cast<zx_handle_t>(36);
constexpr zx_handle_t dummy_handle_14 = static_cast<zx_handle_t>(37);
constexpr zx_handle_t dummy_handle_15 = static_cast<zx_handle_t>(38);
constexpr zx_handle_t dummy_handle_16 = static_cast<zx_handle_t>(39);
constexpr zx_handle_t dummy_handle_17 = static_cast<zx_handle_t>(40);
constexpr zx_handle_t dummy_handle_18 = static_cast<zx_handle_t>(41);
constexpr zx_handle_t dummy_handle_19 = static_cast<zx_handle_t>(42);
constexpr zx_handle_t dummy_handle_20 = static_cast<zx_handle_t>(43);
constexpr zx_handle_t dummy_handle_21 = static_cast<zx_handle_t>(44);
constexpr zx_handle_t dummy_handle_22 = static_cast<zx_handle_t>(45);
constexpr zx_handle_t dummy_handle_23 = static_cast<zx_handle_t>(46);
constexpr zx_handle_t dummy_handle_24 = static_cast<zx_handle_t>(47);
constexpr zx_handle_t dummy_handle_25 = static_cast<zx_handle_t>(48);
constexpr zx_handle_t dummy_handle_26 = static_cast<zx_handle_t>(49);
constexpr zx_handle_t dummy_handle_27 = static_cast<zx_handle_t>(50);
constexpr zx_handle_t dummy_handle_28 = static_cast<zx_handle_t>(51);
constexpr zx_handle_t dummy_handle_29 = static_cast<zx_handle_t>(52);

// All sizes in fidl encoding tables are 32 bits. The fidl compiler
// normally enforces this. Check manually in manual tests.
template <typename T, size_t N>
uint32_t ArrayCount(T const (&array)[N]) {
  static_assert(N < UINT32_MAX, "Array is too large!");
  return N;
}

template <typename T, size_t N>
uint32_t ArraySize(T const (&array)[N]) {
  static_assert(sizeof(array) < UINT32_MAX, "Array is too large!");
  return sizeof(array);
}

#ifdef __Fuchsia__
// Check if the other end of the eventpair is valid
bool IsPeerValid(const zx::unowned_eventpair handle) {
  zx_signals_t observed_signals = {};
  switch (handle->wait_one(ZX_EVENTPAIR_PEER_CLOSED, zx::deadline_after(zx::msec(1)),
                           &observed_signals)) {
    case ZX_ERR_TIMED_OUT:
      // timeout implies peer-closed was not observed
      return true;
    case ZX_OK:
      return (observed_signals & ZX_EVENTPAIR_PEER_CLOSED) == 0;
    default:
      return false;
  }
}
#endif

TEST(NullParameters, decode_null_decode_parameters) {
  zx_handle_t handles[] = {static_cast<zx_handle_t>(23)};

  // Null message type.
  {
    nonnullable_handle_message_layout message = {};
    message.inline_struct.handle = FIDL_HANDLE_PRESENT;
    const char* error = nullptr;
    auto status = fidl_decode(nullptr, &message, sizeof(nonnullable_handle_message_layout), handles,
                              ArrayCount(handles), &error);
    EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
    EXPECT_NOT_NULL(error);
  }

  // Null message.
  {
    const char* error = nullptr;
    auto status = fidl_decode(&nonnullable_handle_message_type, nullptr,
                              sizeof(nonnullable_handle_message_layout), handles,
                              ArrayCount(handles), &error);
    EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
    EXPECT_NOT_NULL(error);
  }

  // Null handles, for a message that has a handle.
  {
    nonnullable_handle_message_layout message = {};
    message.inline_struct.handle = FIDL_HANDLE_PRESENT;
    const char* error = nullptr;
    auto status = fidl_decode(&nonnullable_handle_message_type, &message,
                              sizeof(nonnullable_handle_message_layout), nullptr, 0, &error);
    EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
    EXPECT_NOT_NULL(error);
  }

  // Null handles but positive handle count.
  {
    nonnullable_handle_message_layout message = {};
    message.inline_struct.handle = FIDL_HANDLE_PRESENT;
    const char* error = nullptr;
    auto status = fidl_decode(&nonnullable_handle_message_type, &message,
                              sizeof(nonnullable_handle_message_layout), nullptr, 1, &error);
    EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
    EXPECT_NOT_NULL(error);
  }

  // A null error string pointer is ok, though.
  {
    auto status = fidl_decode(nullptr, nullptr, 0u, nullptr, 0u, nullptr);
    EXPECT_NE(status, ZX_OK);
  }

  // A null error is also ok in success cases.
  {
    nonnullable_handle_message_layout message = {};
    message.inline_struct.handle = FIDL_HANDLE_PRESENT;
    auto status = fidl_decode(&nonnullable_handle_message_type, &message,
                              sizeof(nonnullable_handle_message_layout), handles,
                              ArrayCount(handles), nullptr);
    EXPECT_EQ(status, ZX_OK);
  }
}

TEST(Unaligned, decode_single_present_handle_unaligned_error) {
  // Test a short, unaligned version of nonnullable message
  // handle. All fidl message objects should be 8 byte aligned.
  //
  // We use a byte array rather than fidl_message_header_t to avoid
  // aligning to 8 bytes.
  struct unaligned_nonnullable_handle_inline_data {
    uint8_t header[sizeof(fidl_message_header_t)];
    zx_handle_t handle;
  };
  struct unaligned_nonnullable_handle_message_layout {
    unaligned_nonnullable_handle_inline_data inline_struct;
  };

  unaligned_nonnullable_handle_message_layout message = {};
  message.inline_struct.handle = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
  };

  // Decoding the unaligned version of the struct should fail.
  const char* error = nullptr;
  auto status = fidl_decode(&nonnullable_handle_message_type, &message, sizeof(message), handles,
                            ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Unaligned, decode_present_nonnullable_string_unaligned_error) {
  unbounded_nonnullable_string_message_layout message = {};
  message.inline_struct.string = fidl_string_t{6, reinterpret_cast<char*>(FIDL_ALLOC_PRESENT)};
  memcpy(message.data, "hello!", 6);

  // Copy the message to unaligned storage one byte off from true alignment
  unbounded_nonnullable_string_message_layout message_storage[2];
  uint8_t* unaligned_ptr = reinterpret_cast<uint8_t*>(&message_storage[0]) + 1;
  memcpy(unaligned_ptr, &message, sizeof(message));

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nonnullable_string_message_type, unaligned_ptr,
                            sizeof(message), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
  ASSERT_SUBSTR(error, "must be aligned to FIDL_ALIGNMENT");
}

TEST(Handles, decode_single_present_handle) {
  nonnullable_handle_message_layout message = {};
  message.inline_struct.handle = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&nonnullable_handle_message_type, &message, sizeof(message), handles,
                            ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.handle, dummy_handle_0);
}

TEST(Handles, decode_single_present_handle_check_trailing_padding) {
  // There are four padding bytes; any of them not being zero should lead to an error.
  for (size_t i = 0; i < 4; i++) {
    constexpr size_t kBufferSize = sizeof(nonnullable_handle_message_layout);
    nonnullable_handle_message_layout message;
    uint8_t* buffer = reinterpret_cast<uint8_t*>(&message);
    memset(buffer, 0, kBufferSize);
    message.inline_struct.handle = FIDL_HANDLE_PRESENT;

    buffer[kBufferSize - 4 + i] = 0xAA;

    zx_handle_t handles[] = {
        dummy_handle_0,
    };

    const char* error = nullptr;
    auto status = fidl_decode(&nonnullable_handle_message_type, &message, kBufferSize, handles,
                              ArrayCount(handles), &error);

    EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
    EXPECT_STR_EQ(error, "non-zero padding bytes detected");
  }
}

TEST(Handles, decode_too_many_handles_specified_error) {
  nonnullable_handle_message_layout message = {};
  message.inline_struct.handle = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      ZX_HANDLE_INVALID,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&nonnullable_handle_message_type, &message, sizeof(message), handles,
                            ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
  EXPECT_EQ(message.inline_struct.handle, dummy_handle_0);
}

// Disabled on host due to syscall.
#ifdef __Fuchsia__
TEST(Handles, decode_too_many_handles_specified_should_close_handles) {
  nonnullable_handle_message_layout message = {};
  message.inline_struct.handle = FIDL_HANDLE_PRESENT;

  zx::eventpair ep0, ep1;
  ASSERT_EQ(zx::eventpair::create(0, &ep0, &ep1), ZX_OK);

  zx_handle_t handles[] = {
      ep0.get(),
      ZX_HANDLE_INVALID,
  };

  ASSERT_TRUE(IsPeerValid(zx::unowned_eventpair(ep1)));

  const char* error = nullptr;
  auto status = fidl_decode(&nonnullable_handle_message_type, &message, sizeof(message), handles,
                            ArrayCount(handles), &error);

  ASSERT_EQ(status, ZX_ERR_INVALID_ARGS);
  ASSERT_NOT_NULL(error);
  ASSERT_EQ(message.inline_struct.handle, ep0.get());
  ASSERT_FALSE(IsPeerValid(zx::unowned_eventpair(ep1)));

  // When the test succeeds, |ep0| is closed by the decoder.
  zx_handle_t unused = ep0.release();
  (void)unused;
}

TEST(Handles, decode_too_many_bytes_specified_should_close_handles) {
  constexpr size_t kSizeTooBig = sizeof(nonnullable_handle_message_layout) * 2;
  std::unique_ptr<uint8_t[]> buffer = std::make_unique<uint8_t[]>(kSizeTooBig);
  nonnullable_handle_message_layout& message =
      *reinterpret_cast<nonnullable_handle_message_layout*>(buffer.get());
  message.inline_struct.handle = FIDL_HANDLE_PRESENT;

  zx::eventpair ep0, ep1;
  ASSERT_EQ(zx::eventpair::create(0, &ep0, &ep1), ZX_OK);

  zx_handle_t handles[] = {
      ep0.get(),
  };

  ASSERT_TRUE(IsPeerValid(zx::unowned_eventpair(ep1)));

  const char* error = nullptr;
  auto status = fidl_decode(&nonnullable_handle_message_type, &message, kSizeTooBig, handles,
                            ArrayCount(handles), &error);

  ASSERT_EQ(status, ZX_ERR_INVALID_ARGS);
  ASSERT_NOT_NULL(error);
  ASSERT_EQ(message.inline_struct.handle, ep0.get());
  ASSERT_FALSE(IsPeerValid(zx::unowned_eventpair(ep1)));

  // When the test succeeds, |ep0| is closed by the decoder.
  zx_handle_t unused = ep0.release();
  (void)unused;
}
#endif

TEST(Handles, decode_multiple_present_handles) {
  multiple_nonnullable_handles_message_layout message = {};
  message.inline_struct.handle_0 = FIDL_HANDLE_PRESENT;
  message.inline_struct.handle_1 = FIDL_HANDLE_PRESENT;
  message.inline_struct.handle_2 = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
      dummy_handle_2,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&multiple_nonnullable_handles_message_type, &message, sizeof(message),
                            handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.data_0, 0u);
  EXPECT_EQ(message.inline_struct.handle_0, dummy_handle_0);
  EXPECT_EQ(message.inline_struct.data_1, 0u);
  EXPECT_EQ(message.inline_struct.handle_1, dummy_handle_1);
  EXPECT_EQ(message.inline_struct.handle_2, dummy_handle_2);
  EXPECT_EQ(message.inline_struct.data_2, 0u);
}

TEST(Handles, decode_single_absent_handle) {
  nullable_handle_message_layout message = {};
  message.inline_struct.handle = FIDL_HANDLE_ABSENT;

  const char* error = nullptr;
  auto status =
      fidl_decode(&nullable_handle_message_type, &message, sizeof(message), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.handle, ZX_HANDLE_INVALID);
}

TEST(Handles, decode_multiple_absent_handles) {
  multiple_nullable_handles_message_layout message = {};
  message.inline_struct.handle_0 = FIDL_HANDLE_ABSENT;
  message.inline_struct.handle_1 = FIDL_HANDLE_ABSENT;
  message.inline_struct.handle_2 = FIDL_HANDLE_ABSENT;

  const char* error = nullptr;
  auto status = fidl_decode(&multiple_nullable_handles_message_type, &message, sizeof(message),
                            nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.data_0, 0u);
  EXPECT_EQ(message.inline_struct.handle_0, ZX_HANDLE_INVALID);
  EXPECT_EQ(message.inline_struct.data_1, 0u);
  EXPECT_EQ(message.inline_struct.handle_1, ZX_HANDLE_INVALID);
  EXPECT_EQ(message.inline_struct.handle_2, ZX_HANDLE_INVALID);
  EXPECT_EQ(message.inline_struct.data_2, 0u);
}

TEST(Arrays, decode_array_of_present_handles) {
  array_of_nonnullable_handles_message_layout message = {};
  message.inline_struct.handles[0] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[1] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[2] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[3] = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
      dummy_handle_2,
      dummy_handle_3,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&array_of_nonnullable_handles_message_type, &message, sizeof(message),
                            handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.handles[0], dummy_handle_0);
  EXPECT_EQ(message.inline_struct.handles[1], dummy_handle_1);
  EXPECT_EQ(message.inline_struct.handles[2], dummy_handle_2);
  EXPECT_EQ(message.inline_struct.handles[3], dummy_handle_3);
}

// Disabled on host due to syscall.
#ifdef __Fuchsia__
TEST(Arrays, decode_array_of_present_handles_error_closes_handles) {
  array_of_nonnullable_handles_message_layout message = {};
  zx_handle_t handle_pairs[4][2];
  // Use eventpairs so that we can know for sure that handles were closed by fidl_decode.
  for (uint32_t i = 0; i < ArrayCount(handle_pairs); ++i) {
    ASSERT_EQ(zx_eventpair_create(0u, &handle_pairs[i][0], &handle_pairs[i][1]), ZX_OK);
  }
  message.inline_struct.handles[0] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[1] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[2] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[3] = FIDL_HANDLE_PRESENT;

  zx_handle_t out_of_line_handles[4] = {
      handle_pairs[0][0],
      handle_pairs[1][0],
      handle_pairs[2][0],
      handle_pairs[3][0],
  };

  const char* error = nullptr;
  auto status = fidl_decode(&array_of_nonnullable_handles_message_type, &message, sizeof(message),
                            out_of_line_handles,
                            // -2 makes this invalid.
                            ArrayCount(out_of_line_handles) - 2, &error);
  // Should fail because we we pass in a max_handles < the actual number of handles.
  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  // All the handles that we told fidl_decode about should be closed.
  uint32_t i;
  for (i = 0; i < ArrayCount(handle_pairs) - 2; ++i) {
    zx_signals_t observed_signals;
    EXPECT_EQ(zx_object_wait_one(handle_pairs[i][1], ZX_EVENTPAIR_PEER_CLOSED,
                                 1,  // deadline shouldn't matter, should return immediately.
                                 &observed_signals),
              ZX_OK);
    EXPECT_EQ(observed_signals & ZX_EVENTPAIR_PEER_CLOSED, ZX_EVENTPAIR_PEER_CLOSED);
    EXPECT_EQ(zx_handle_close(handle_pairs[i][1]), ZX_OK);  // [i][0] was closed by fidl_encode.
  }
  // But the other ones should not be.
  for (; i < ArrayCount(handle_pairs); ++i) {
    zx_signals_t observed_signals;
    EXPECT_EQ(zx_object_wait_one(handle_pairs[i][1], ZX_EVENTPAIR_PEER_CLOSED,
                                 zx_clock_get_monotonic() + 1, &observed_signals),
              ZX_ERR_TIMED_OUT);
    EXPECT_EQ(observed_signals & ZX_EVENTPAIR_PEER_CLOSED, 0);
    EXPECT_EQ(zx_handle_close(handle_pairs[i][0]), ZX_OK);
    EXPECT_EQ(zx_handle_close(handle_pairs[i][1]), ZX_OK);
  }
}
#endif

TEST(Arrays, decode_array_of_nonnullable_handles_some_absent_error) {
  array_of_nonnullable_handles_message_layout message = {};
  message.inline_struct.handles[0] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[1] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[2] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[3] = FIDL_HANDLE_ABSENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
      dummy_handle_2,
      dummy_handle_3,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&array_of_nonnullable_handles_message_type, &message, sizeof(message),
                            handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Arrays, decode_array_of_nullable_handles) {
  array_of_nullable_handles_message_layout message = {};
  message.inline_struct.handles[0] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[1] = FIDL_HANDLE_ABSENT;
  message.inline_struct.handles[2] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[3] = FIDL_HANDLE_ABSENT;
  message.inline_struct.handles[4] = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
      dummy_handle_2,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&array_of_nullable_handles_message_type, &message, sizeof(message),
                            handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.handles[0], dummy_handle_0);
  EXPECT_EQ(message.inline_struct.handles[1], ZX_HANDLE_INVALID);
  EXPECT_EQ(message.inline_struct.handles[2], dummy_handle_1);
  EXPECT_EQ(message.inline_struct.handles[3], ZX_HANDLE_INVALID);
  EXPECT_EQ(message.inline_struct.handles[4], dummy_handle_2);
}

TEST(Arrays, decode_array_of_nullable_handles_with_insufficient_handles_error) {
  array_of_nullable_handles_message_layout message = {};
  message.inline_struct.handles[0] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[1] = FIDL_HANDLE_ABSENT;
  message.inline_struct.handles[2] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[3] = FIDL_HANDLE_ABSENT;
  message.inline_struct.handles[4] = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&array_of_nullable_handles_message_type, &message, sizeof(message),
                            handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Arrays, decode_array_of_array_of_present_handles) {
  array_of_array_of_nonnullable_handles_message_layout message = {};
  message.inline_struct.handles[0][0] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[0][1] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[0][2] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[0][3] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[1][0] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[1][1] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[1][2] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[1][3] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[2][0] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[2][1] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[2][2] = FIDL_HANDLE_PRESENT;
  message.inline_struct.handles[2][3] = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0, dummy_handle_1, dummy_handle_2,  dummy_handle_3,
      dummy_handle_4, dummy_handle_5, dummy_handle_6,  dummy_handle_7,
      dummy_handle_8, dummy_handle_9, dummy_handle_10, dummy_handle_11,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&array_of_array_of_nonnullable_handles_message_type, &message,
                            sizeof(message), handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.handles[0][0], dummy_handle_0);
  EXPECT_EQ(message.inline_struct.handles[0][1], dummy_handle_1);
  EXPECT_EQ(message.inline_struct.handles[0][2], dummy_handle_2);
  EXPECT_EQ(message.inline_struct.handles[0][3], dummy_handle_3);
  EXPECT_EQ(message.inline_struct.handles[1][0], dummy_handle_4);
  EXPECT_EQ(message.inline_struct.handles[1][1], dummy_handle_5);
  EXPECT_EQ(message.inline_struct.handles[1][2], dummy_handle_6);
  EXPECT_EQ(message.inline_struct.handles[1][3], dummy_handle_7);
  EXPECT_EQ(message.inline_struct.handles[2][0], dummy_handle_8);
  EXPECT_EQ(message.inline_struct.handles[2][1], dummy_handle_9);
  EXPECT_EQ(message.inline_struct.handles[2][2], dummy_handle_10);
  EXPECT_EQ(message.inline_struct.handles[2][3], dummy_handle_11);
}

TEST(Arrays, decode_out_of_line_array) {
  out_of_line_array_of_nonnullable_handles_message_layout message = {};
  message.inline_struct.maybe_array =
      reinterpret_cast<array_of_nonnullable_handles*>(FIDL_ALLOC_PRESENT);
  message.data.handles[0] = FIDL_HANDLE_PRESENT;
  message.data.handles[1] = FIDL_HANDLE_PRESENT;
  message.data.handles[2] = FIDL_HANDLE_PRESENT;
  message.data.handles[3] = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
      dummy_handle_2,
      dummy_handle_3,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&out_of_line_array_of_nonnullable_handles_message_type, &message,
                            sizeof(message), handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto array_ptr = message.inline_struct.maybe_array;
  EXPECT_NOT_NULL(array_ptr);
  EXPECT_EQ(array_ptr->handles[0], dummy_handle_0);
  EXPECT_EQ(array_ptr->handles[1], dummy_handle_1);
  EXPECT_EQ(array_ptr->handles[2], dummy_handle_2);
  EXPECT_EQ(array_ptr->handles[3], dummy_handle_3);
}

TEST(Strings, decode_present_nonnullable_string) {
  unbounded_nonnullable_string_message_layout message = {};
  message.inline_struct.string = fidl_string_t{6, reinterpret_cast<char*>(FIDL_ALLOC_PRESENT)};
  memcpy(message.data, "hello!", 6);

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nonnullable_string_message_type, &message, sizeof(message),
                            nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.string.size, 6);
  EXPECT_EQ(message.inline_struct.string.data[0], 'h');
  EXPECT_EQ(message.inline_struct.string.data[1], 'e');
  EXPECT_EQ(message.inline_struct.string.data[2], 'l');
  EXPECT_EQ(message.inline_struct.string.data[3], 'l');
  EXPECT_EQ(message.inline_struct.string.data[4], 'o');
  EXPECT_EQ(message.inline_struct.string.data[5], '!');
}

TEST(Strings, decode_present_nullable_string) {
  unbounded_nullable_string_message_layout message = {};
  message.inline_struct.string = fidl_string_t{6, reinterpret_cast<char*>(FIDL_ALLOC_PRESENT)};
  memcpy(message.data, "hello!", 6);

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nullable_string_message_type, &message, sizeof(message),
                            nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.string.size, 6);
  EXPECT_EQ(message.inline_struct.string.data[0], 'h');
  EXPECT_EQ(message.inline_struct.string.data[1], 'e');
  EXPECT_EQ(message.inline_struct.string.data[2], 'l');
  EXPECT_EQ(message.inline_struct.string.data[3], 'l');
  EXPECT_EQ(message.inline_struct.string.data[4], 'o');
  EXPECT_EQ(message.inline_struct.string.data[5], '!');
}

TEST(Strings, decode_multiple_present_nullable_string) {
  // Among other things, this test ensures we handle out-of-line
  // alignment to FIDL_ALIGNMENT (i.e., 8) bytes correctly.
  multiple_nullable_strings_message_layout message;
  memset(&message, 0, sizeof(message));

  message.inline_struct.string = fidl_string_t{6, reinterpret_cast<char*>(FIDL_ALLOC_PRESENT)};
  message.inline_struct.string2 = fidl_string_t{8, reinterpret_cast<char*>(FIDL_ALLOC_PRESENT)};
  memcpy(message.data, "hello ", 6);
  memcpy(message.data2, "world!!! ", 8);

  const char* error = nullptr;
  auto status = fidl_decode(&multiple_nullable_strings_message_type, &message, sizeof(message),
                            nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.string.size, 6);
  EXPECT_EQ(message.inline_struct.string.data[0], 'h');
  EXPECT_EQ(message.inline_struct.string.data[1], 'e');
  EXPECT_EQ(message.inline_struct.string.data[2], 'l');
  EXPECT_EQ(message.inline_struct.string.data[3], 'l');
  EXPECT_EQ(message.inline_struct.string.data[4], 'o');
  EXPECT_EQ(message.inline_struct.string.data[5], ' ');
  EXPECT_EQ(message.inline_struct.string2.size, 8);
  EXPECT_EQ(message.inline_struct.string2.data[0], 'w');
  EXPECT_EQ(message.inline_struct.string2.data[1], 'o');
  EXPECT_EQ(message.inline_struct.string2.data[2], 'r');
  EXPECT_EQ(message.inline_struct.string2.data[3], 'l');
  EXPECT_EQ(message.inline_struct.string2.data[4], 'd');
  EXPECT_EQ(message.inline_struct.string2.data[5], '!');
  EXPECT_EQ(message.inline_struct.string2.data[6], '!');
  EXPECT_EQ(message.inline_struct.string2.data[7], '!');
  EXPECT_EQ(message.inline_struct.string2.data[7], '!');
}

TEST(Strings, decode_absent_nonnullable_string_error) {
  unbounded_nonnullable_string_message_layout message = {};
  message.inline_struct.string = fidl_string_t{6, reinterpret_cast<char*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nonnullable_string_message_type, &message, sizeof(message),
                            nullptr, 0, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Strings, decode_absent_nullable_string) {
  unbounded_nullable_string_message_layout message = {};
  message.inline_struct.string = fidl_string_t{0, reinterpret_cast<char*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nullable_string_message_type, &message,
                            sizeof(message.inline_struct), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
}

TEST(Strings, decode_present_nonnullable_bounded_string) {
  bounded_32_nonnullable_string_message_layout message = {};
  message.inline_struct.string = fidl_string_t{6, reinterpret_cast<char*>(FIDL_ALLOC_PRESENT)};
  memcpy(message.data, "hello!", 6);

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nonnullable_string_message_type, &message, sizeof(message),
                            nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.string.size, 6);
  EXPECT_EQ(message.inline_struct.string.data[0], 'h');
  EXPECT_EQ(message.inline_struct.string.data[1], 'e');
  EXPECT_EQ(message.inline_struct.string.data[2], 'l');
  EXPECT_EQ(message.inline_struct.string.data[3], 'l');
  EXPECT_EQ(message.inline_struct.string.data[4], 'o');
  EXPECT_EQ(message.inline_struct.string.data[5], '!');
}

TEST(Strings, decode_present_nullable_bounded_string) {
  bounded_32_nullable_string_message_layout message = {};
  message.inline_struct.string = fidl_string_t{6, reinterpret_cast<char*>(FIDL_ALLOC_PRESENT)};
  memcpy(message.data, "hello!", 6);

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nullable_string_message_type, &message, sizeof(message),
                            nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.string.size, 6);
  EXPECT_EQ(message.inline_struct.string.data[0], 'h');
  EXPECT_EQ(message.inline_struct.string.data[1], 'e');
  EXPECT_EQ(message.inline_struct.string.data[2], 'l');
  EXPECT_EQ(message.inline_struct.string.data[3], 'l');
  EXPECT_EQ(message.inline_struct.string.data[4], 'o');
  EXPECT_EQ(message.inline_struct.string.data[5], '!');
}

TEST(Strings, decode_absent_nonnullable_bounded_string_error) {
  bounded_32_nonnullable_string_message_layout message = {};
  message.inline_struct.string = fidl_string_t{6, reinterpret_cast<char*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nonnullable_string_message_type, &message, sizeof(message),
                            nullptr, 0, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Strings, decode_absent_nullable_bounded_string) {
  bounded_32_nullable_string_message_layout message = {};
  message.inline_struct.string = fidl_string_t{0, reinterpret_cast<char*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nullable_string_message_type, &message,
                            sizeof(message.inline_struct), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
}

TEST(Strings, decode_present_nonnullable_bounded_string_short_error) {
  multiple_short_nonnullable_strings_message_layout message = {};
  message.inline_struct.string = fidl_string_t{6, reinterpret_cast<char*>(FIDL_ALLOC_PRESENT)};
  message.inline_struct.string2 = fidl_string_t{8, reinterpret_cast<char*>(FIDL_ALLOC_PRESENT)};
  memcpy(message.data, "hello ", 6);
  memcpy(message.data2, "world! ", 6);

  const char* error = nullptr;
  auto status = fidl_decode(&multiple_short_nonnullable_strings_message_type, &message,
                            sizeof(message), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Strings, decode_present_nullable_bounded_string_short_error) {
  multiple_short_nullable_strings_message_layout message = {};
  message.inline_struct.string = fidl_string_t{6, reinterpret_cast<char*>(FIDL_ALLOC_PRESENT)};
  message.inline_struct.string2 = fidl_string_t{8, reinterpret_cast<char*>(FIDL_ALLOC_PRESENT)};
  memcpy(message.data, "hello ", 6);
  memcpy(message.data2, "world! ", 6);

  const char* error = nullptr;
  auto status = fidl_decode(&multiple_short_nullable_strings_message_type, &message,
                            sizeof(message), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Vectors, decode_vector_with_huge_count) {
  unbounded_nonnullable_vector_of_uint32_message_layout message = {};
  // (2^30 + 4) * 4 (4 == sizeof(uint32_t)) overflows to 16 when stored as uint32_t.
  // We want 16 because it happens to be the actual size of the vector data in the message,
  // so we can trigger the overflow without triggering the "tried to claim too many bytes" or
  // "didn't use all the bytes in the message" errors.
  message.inline_struct.vector =
      fidl_vector_t{(1ull << 30) + 4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nonnullable_vector_of_uint32_message_type, &message,
                            sizeof(message), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
  const char expected_error_msg[] = "integer overflow calculating vector size";
  EXPECT_STR_EQ(expected_error_msg, error, "wrong error msg");

  auto message_uint32 = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_NOT_NULL(message_uint32);
}

TEST(Vectors, decode_present_nonnullable_vector_of_handles) {
  unbounded_nonnullable_vector_of_handles_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};
  message.handles[0] = FIDL_HANDLE_PRESENT;
  message.handles[1] = FIDL_HANDLE_PRESENT;
  message.handles[2] = FIDL_HANDLE_PRESENT;
  message.handles[3] = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
      dummy_handle_2,
      dummy_handle_3,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nonnullable_vector_of_handles_message_type, &message,
                            sizeof(message), handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_handles = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_EQ(message_handles[0], dummy_handle_0);
  EXPECT_EQ(message_handles[1], dummy_handle_1);
  EXPECT_EQ(message_handles[2], dummy_handle_2);
  EXPECT_EQ(message_handles[3], dummy_handle_3);
}

TEST(Vectors, decode_present_nullable_vector_of_handles) {
  unbounded_nullable_vector_of_handles_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};
  message.handles[0] = FIDL_HANDLE_PRESENT;
  message.handles[1] = FIDL_HANDLE_PRESENT;
  message.handles[2] = FIDL_HANDLE_PRESENT;
  message.handles[3] = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
      dummy_handle_2,
      dummy_handle_3,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nullable_vector_of_handles_message_type, &message,
                            sizeof(message), handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_handles = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_EQ(message_handles[0], dummy_handle_0);
  EXPECT_EQ(message_handles[1], dummy_handle_1);
  EXPECT_EQ(message_handles[2], dummy_handle_2);
  EXPECT_EQ(message_handles[3], dummy_handle_3);
}

TEST(Vectors, decode_absent_nonnullable_vector_of_handles_error) {
  unbounded_nonnullable_vector_of_handles_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_ABSENT)};

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
      dummy_handle_2,
      dummy_handle_3,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nonnullable_vector_of_handles_message_type, &message,
                            sizeof(message), handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Vectors, decode_absent_nullable_vector_of_handles) {
  unbounded_nullable_vector_of_handles_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{0, reinterpret_cast<void*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nullable_vector_of_handles_message_type, &message,
                            sizeof(message.inline_struct), nullptr, 0u, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_handles = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_NULL(message_handles);
}

TEST(Vectors, decode_present_nonnullable_bounded_vector_of_handles) {
  bounded_32_nonnullable_vector_of_handles_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};
  message.handles[0] = FIDL_HANDLE_PRESENT;
  message.handles[1] = FIDL_HANDLE_PRESENT;
  message.handles[2] = FIDL_HANDLE_PRESENT;
  message.handles[3] = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
      dummy_handle_2,
      dummy_handle_3,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nonnullable_vector_of_handles_message_type, &message,
                            sizeof(message), handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_handles = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_EQ(message_handles[0], dummy_handle_0);
  EXPECT_EQ(message_handles[1], dummy_handle_1);
  EXPECT_EQ(message_handles[2], dummy_handle_2);
  EXPECT_EQ(message_handles[3], dummy_handle_3);
}

TEST(Vectors, decode_present_nullable_bounded_vector_of_handles) {
  bounded_32_nullable_vector_of_handles_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};
  message.handles[0] = FIDL_HANDLE_PRESENT;
  message.handles[1] = FIDL_HANDLE_PRESENT;
  message.handles[2] = FIDL_HANDLE_PRESENT;
  message.handles[3] = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
      dummy_handle_2,
      dummy_handle_3,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nullable_vector_of_handles_message_type, &message,
                            sizeof(message), handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_handles = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_EQ(message_handles[0], dummy_handle_0);
  EXPECT_EQ(message_handles[1], dummy_handle_1);
  EXPECT_EQ(message_handles[2], dummy_handle_2);
  EXPECT_EQ(message_handles[3], dummy_handle_3);
}

TEST(Vectors, decode_absent_nonnullable_bounded_vector_of_handles) {
  bounded_32_nonnullable_vector_of_handles_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nonnullable_vector_of_handles_message_type, &message,
                            sizeof(message.inline_struct), nullptr, 0u, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);

  auto message_handles = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_NULL(message_handles);
}

TEST(Vectors, decode_absent_nullable_bounded_vector_of_handles) {
  bounded_32_nullable_vector_of_handles_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{0, reinterpret_cast<void*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nullable_vector_of_handles_message_type, &message,
                            sizeof(message.inline_struct), nullptr, 0u, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_handles = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_NULL(message_handles);
}

TEST(Vectors, decode_present_nonnullable_bounded_vector_of_handles_short_error) {
  multiple_nonnullable_vectors_of_handles_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};
  message.inline_struct.vector2 = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};
  message.handles[0] = FIDL_HANDLE_PRESENT;
  message.handles[1] = FIDL_HANDLE_PRESENT;
  message.handles[2] = FIDL_HANDLE_PRESENT;
  message.handles[3] = FIDL_HANDLE_PRESENT;
  message.handles2[0] = FIDL_HANDLE_PRESENT;
  message.handles2[1] = FIDL_HANDLE_PRESENT;
  message.handles2[2] = FIDL_HANDLE_PRESENT;
  message.handles2[3] = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0, dummy_handle_1, dummy_handle_2, dummy_handle_3,
      dummy_handle_4, dummy_handle_5, dummy_handle_6, dummy_handle_7,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&multiple_nonnullable_vectors_of_handles_message_type, &message,
                            sizeof(message), handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Vectors, decode_present_nullable_bounded_vector_of_handles_short_error) {
  multiple_nullable_vectors_of_handles_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};
  message.inline_struct.vector2 = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};
  message.handles[0] = FIDL_HANDLE_PRESENT;
  message.handles[1] = FIDL_HANDLE_PRESENT;
  message.handles[2] = FIDL_HANDLE_PRESENT;
  message.handles[3] = FIDL_HANDLE_PRESENT;
  message.handles2[0] = FIDL_HANDLE_PRESENT;
  message.handles2[1] = FIDL_HANDLE_PRESENT;
  message.handles2[2] = FIDL_HANDLE_PRESENT;
  message.handles2[3] = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0, dummy_handle_1, dummy_handle_2, dummy_handle_3,
      dummy_handle_4, dummy_handle_5, dummy_handle_6, dummy_handle_7,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&multiple_nullable_vectors_of_handles_message_type, &message,
                            sizeof(message), handles, ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Vectors, decode_present_nonnullable_vector_of_uint32) {
  unbounded_nonnullable_vector_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nonnullable_vector_of_uint32_message_type, &message,
                            sizeof(message), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_uint32 = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_NOT_NULL(message_uint32);
}

TEST(Vectors, decode_present_nullable_vector_of_uint32) {
  unbounded_nullable_vector_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nullable_vector_of_uint32_message_type, &message,
                            sizeof(message), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_uint32 = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_NOT_NULL(message_uint32);
}

TEST(Vectors, decode_absent_nonnullable_vector_of_uint32_error) {
  unbounded_nonnullable_vector_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nonnullable_vector_of_uint32_message_type, &message,
                            sizeof(message.inline_struct), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Vectors, decode_absent_and_empty_nonnullable_vector_of_uint32_error) {
  unbounded_nonnullable_vector_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{0, reinterpret_cast<void*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nonnullable_vector_of_uint32_message_type, &message,
                            sizeof(message.inline_struct), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Vectors, decode_absent_nullable_vector_of_uint32) {
  unbounded_nullable_vector_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{0, reinterpret_cast<void*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nullable_vector_of_uint32_message_type, &message,
                            sizeof(message.inline_struct), nullptr, 0u, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_uint32 = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_NULL(message_uint32);
}

TEST(Vectors, decode_absent_nullable_vector_of_uint32_non_zero_length_error) {
  unbounded_nullable_vector_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&unbounded_nullable_vector_of_uint32_message_type, &message,
                            sizeof(message.inline_struct), nullptr, 0u, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Vectors, decode_present_nonnullable_bounded_vector_of_uint32) {
  bounded_32_nonnullable_vector_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nonnullable_vector_of_uint32_message_type, &message,
                            sizeof(message), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_uint32 = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_NOT_NULL(message_uint32);
}

TEST(Vectors, decode_present_nullable_bounded_vector_of_uint32) {
  bounded_32_nullable_vector_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nullable_vector_of_uint32_message_type, &message,
                            sizeof(message), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_uint32 = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_NOT_NULL(message_uint32);
}

TEST(Vectors, decode_absent_nonnullable_bounded_vector_of_uint32) {
  bounded_32_nonnullable_vector_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nonnullable_vector_of_uint32_message_type, &message,
                            sizeof(message.inline_struct), nullptr, 0u, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);

  auto message_uint32 = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_NULL(message_uint32);
}

TEST(Vectors, decode_absent_nullable_bounded_vector_of_uint32) {
  bounded_32_nullable_vector_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{0, reinterpret_cast<void*>(FIDL_ALLOC_ABSENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&bounded_32_nullable_vector_of_uint32_message_type, &message,
                            sizeof(message.inline_struct), nullptr, 0u, &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  auto message_uint32 = reinterpret_cast<zx_handle_t*>(message.inline_struct.vector.data);
  EXPECT_NULL(message_uint32);
}

TEST(Vectors, decode_present_nonnullable_bounded_vector_of_uint32_short_error) {
  multiple_nonnullable_vectors_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};
  message.inline_struct.vector2 = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&multiple_nonnullable_vectors_of_uint32_message_type, &message,
                            sizeof(message), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Vectors, decode_present_nullable_bounded_vector_of_uint32_short_error) {
  multiple_nullable_vectors_of_uint32_message_layout message = {};
  message.inline_struct.vector = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};
  message.inline_struct.vector2 = fidl_vector_t{4, reinterpret_cast<void*>(FIDL_ALLOC_PRESENT)};

  const char* error = nullptr;
  auto status = fidl_decode(&multiple_nullable_vectors_of_uint32_message_type, &message,
                            sizeof(message), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
}

TEST(Structs, decode_nested_nonnullable_structs) {
  nested_structs_message_layout message = {};
  message.inline_struct.l0.handle_0 = FIDL_HANDLE_PRESENT;
  message.inline_struct.l0.l1.handle_1 = FIDL_HANDLE_PRESENT;
  message.inline_struct.l0.l1.l2.handle_2 = FIDL_HANDLE_PRESENT;
  message.inline_struct.l0.l1.l2.l3.handle_3 = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,
      dummy_handle_1,
      dummy_handle_2,
      dummy_handle_3,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&nested_structs_message_type, &message, sizeof(message), handles,
                            ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  // Note the traversal order! l1 -> l3 -> l2 -> l0
  EXPECT_EQ(message.inline_struct.l0.l1.handle_1, dummy_handle_0);
  EXPECT_EQ(message.inline_struct.l0.l1.l2.l3.handle_3, dummy_handle_1);
  EXPECT_EQ(message.inline_struct.l0.l1.l2.handle_2, dummy_handle_2);
  EXPECT_EQ(message.inline_struct.l0.handle_0, dummy_handle_3);
}

TEST(Structs, decode_nested_nonnullable_structs_check_padding) {
  // Wire-format:
  // message
  // - 16 bytes header
  // + struct_level_0  -------------  offset 16 = 4 * 4
  //   - uint64_t
  //   + struct_level_1  -----------  offset 24 = 4 * 6
  //     - zx_handle_t
  //     - (4 bytes padding)  ------  offset 28 = 4 * 7
  //     + struct_level_2  ---------  offset 32 = 4 * 8
  //       - uint64_t
  //       + struct_level_3  -------  offset 40 = 4 * 10
  //         - uint32_t
  //         - zx_handle_t
  //       - zx_handle_t
  //       - (4 bytes padding)  ----  offset 52 = 4 * 13
  //     - uint64_t
  //   - zx_handle_t
  //   - (4 bytes padding)  --------  offset 68 = 4 * 17
  static_assert(sizeof(nested_structs_message_layout) == 68 + 4);
  // Hence the padding bytes are located at:
  size_t padding_offsets[] = {
      28, 29, 30, 31, 52, 53, 54, 55, 68, 69, 70, 71,
  };

  for (const auto padding_offset : padding_offsets) {
    constexpr size_t kBufferSize = sizeof(nested_structs_message_layout);
    nested_structs_message_layout message;
    uint8_t* buffer = reinterpret_cast<uint8_t*>(&message);
    memset(buffer, 0, kBufferSize);

    message.inline_struct.l0.handle_0 = FIDL_HANDLE_PRESENT;
    message.inline_struct.l0.l1.handle_1 = FIDL_HANDLE_PRESENT;
    message.inline_struct.l0.l1.l2.handle_2 = FIDL_HANDLE_PRESENT;
    message.inline_struct.l0.l1.l2.l3.handle_3 = FIDL_HANDLE_PRESENT;

    buffer[padding_offset] = 0xAA;

    zx_handle_t handles[] = {
        dummy_handle_0,
        dummy_handle_1,
        dummy_handle_2,
        dummy_handle_3,
    };

    const char* error = nullptr;
    auto status = fidl_decode(&nested_structs_message_type, &message, kBufferSize, handles,
                              ArrayCount(handles), &error);

    EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
    ASSERT_NOT_NULL(error);
    EXPECT_STR_EQ(error, "non-zero padding bytes detected");
  }
}

TEST(Structs, decode_nested_nullable_structs) {
  // See below for the handle traversal order.
  nested_struct_ptrs_message_layout message = {};

  message.inline_struct.l0_present = reinterpret_cast<struct_ptr_level_0*>(FIDL_ALLOC_PRESENT);
  message.inline_struct.l0_inline.l1_present =
      reinterpret_cast<struct_ptr_level_1*>(FIDL_ALLOC_PRESENT);
  message.inline_struct.l0_inline.l1_inline.l2_present =
      reinterpret_cast<struct_ptr_level_2*>(FIDL_ALLOC_PRESENT);
  message.inline_struct.l0_inline.l1_inline.l2_inline.l3_present =
      reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_PRESENT);
  message.in_in_out_2.l3_present = reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_PRESENT);
  message.in_out_1.l2_present = reinterpret_cast<struct_ptr_level_2*>(FIDL_ALLOC_PRESENT);
  message.in_out_1.l2_inline.l3_present = reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_PRESENT);
  message.in_out_out_2.l3_present = reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_PRESENT);
  message.out_0.l1_present = reinterpret_cast<struct_ptr_level_1*>(FIDL_ALLOC_PRESENT);
  message.out_0.l1_inline.l2_present = reinterpret_cast<struct_ptr_level_2*>(FIDL_ALLOC_PRESENT);
  message.out_0.l1_inline.l2_inline.l3_present =
      reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_PRESENT);
  message.out_in_out_2.l3_present = reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_PRESENT);
  message.out_out_1.l2_present = reinterpret_cast<struct_ptr_level_2*>(FIDL_ALLOC_PRESENT);
  message.out_out_1.l2_inline.l3_present =
      reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_PRESENT);
  message.out_out_out_2.l3_present = reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_PRESENT);

  message.inline_struct.l0_absent = reinterpret_cast<struct_ptr_level_0*>(FIDL_ALLOC_ABSENT);
  message.inline_struct.l0_inline.l1_absent =
      reinterpret_cast<struct_ptr_level_1*>(FIDL_ALLOC_ABSENT);
  message.inline_struct.l0_inline.l1_inline.l2_absent =
      reinterpret_cast<struct_ptr_level_2*>(FIDL_ALLOC_ABSENT);
  message.inline_struct.l0_inline.l1_inline.l2_inline.l3_absent =
      reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_ABSENT);
  message.in_in_out_2.l3_absent = reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_ABSENT);
  message.in_out_1.l2_absent = reinterpret_cast<struct_ptr_level_2*>(FIDL_ALLOC_ABSENT);
  message.in_out_1.l2_inline.l3_absent = reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_ABSENT);
  message.in_out_out_2.l3_absent = reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_ABSENT);
  message.out_0.l1_absent = reinterpret_cast<struct_ptr_level_1*>(FIDL_ALLOC_ABSENT);
  message.out_0.l1_inline.l2_absent = reinterpret_cast<struct_ptr_level_2*>(FIDL_ALLOC_ABSENT);
  message.out_0.l1_inline.l2_inline.l3_absent =
      reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_ABSENT);
  message.out_in_out_2.l3_absent = reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_ABSENT);
  message.out_out_1.l2_absent = reinterpret_cast<struct_ptr_level_2*>(FIDL_ALLOC_ABSENT);
  message.out_out_1.l2_inline.l3_absent = reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_ABSENT);
  message.out_out_out_2.l3_absent = reinterpret_cast<struct_ptr_level_3*>(FIDL_ALLOC_ABSENT);

  message.inline_struct.l0_inline.l1_inline.handle_1 = FIDL_HANDLE_PRESENT;
  message.in_in_out_out_3.handle_3 = FIDL_HANDLE_PRESENT;
  message.in_in_out_2.l3_inline.handle_3 = FIDL_HANDLE_PRESENT;
  message.in_in_out_2.handle_2 = FIDL_HANDLE_PRESENT;
  message.in_in_in_out_3.handle_3 = FIDL_HANDLE_PRESENT;
  message.inline_struct.l0_inline.l1_inline.l2_inline.l3_inline.handle_3 = FIDL_HANDLE_PRESENT;
  message.inline_struct.l0_inline.l1_inline.l2_inline.handle_2 = FIDL_HANDLE_PRESENT;
  message.inline_struct.l0_inline.handle_0 = FIDL_HANDLE_PRESENT;
  message.in_out_1.handle_1 = FIDL_HANDLE_PRESENT;
  message.in_out_out_out_3.handle_3 = FIDL_HANDLE_PRESENT;
  message.in_out_out_2.l3_inline.handle_3 = FIDL_HANDLE_PRESENT;
  message.in_out_out_2.handle_2 = FIDL_HANDLE_PRESENT;
  message.in_out_in_out_3.handle_3 = FIDL_HANDLE_PRESENT;
  message.in_out_1.l2_inline.l3_inline.handle_3 = FIDL_HANDLE_PRESENT;
  message.in_out_1.l2_inline.handle_2 = FIDL_HANDLE_PRESENT;
  message.out_0.l1_inline.handle_1 = FIDL_HANDLE_PRESENT;
  message.out_in_out_out_3.handle_3 = FIDL_HANDLE_PRESENT;
  message.out_in_out_2.l3_inline.handle_3 = FIDL_HANDLE_PRESENT;
  message.out_in_out_2.handle_2 = FIDL_HANDLE_PRESENT;
  message.out_in_in_out_3.handle_3 = FIDL_HANDLE_PRESENT;
  message.out_0.l1_inline.l2_inline.l3_inline.handle_3 = FIDL_HANDLE_PRESENT;
  message.out_0.l1_inline.l2_inline.handle_2 = FIDL_HANDLE_PRESENT;
  message.out_0.handle_0 = FIDL_HANDLE_PRESENT;
  message.out_out_1.handle_1 = FIDL_HANDLE_PRESENT;
  message.out_out_out_out_3.handle_3 = FIDL_HANDLE_PRESENT;
  message.out_out_out_2.l3_inline.handle_3 = FIDL_HANDLE_PRESENT;
  message.out_out_out_2.handle_2 = FIDL_HANDLE_PRESENT;
  message.out_out_in_out_3.handle_3 = FIDL_HANDLE_PRESENT;
  message.out_out_1.l2_inline.l3_inline.handle_3 = FIDL_HANDLE_PRESENT;
  message.out_out_1.l2_inline.handle_2 = FIDL_HANDLE_PRESENT;

  zx_handle_t handles[] = {
      dummy_handle_0,  dummy_handle_1,  dummy_handle_2,  dummy_handle_3,  dummy_handle_4,
      dummy_handle_5,  dummy_handle_6,  dummy_handle_7,  dummy_handle_8,  dummy_handle_9,
      dummy_handle_10, dummy_handle_11, dummy_handle_12, dummy_handle_13, dummy_handle_14,
      dummy_handle_15, dummy_handle_16, dummy_handle_17, dummy_handle_18, dummy_handle_19,
      dummy_handle_20, dummy_handle_21, dummy_handle_22, dummy_handle_23, dummy_handle_24,
      dummy_handle_25, dummy_handle_26, dummy_handle_27, dummy_handle_28, dummy_handle_29,
  };

  const char* error = nullptr;
  auto status = fidl_decode(&nested_struct_ptrs_message_type, &message, sizeof(message), handles,
                            ArrayCount(handles), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);

  // Note the traversal order!

  // 0 inline
  //     1 inline
  //         handle
  EXPECT_EQ(message.inline_struct.l0_inline.l1_inline.handle_1, dummy_handle_0);
  //         2 out of line
  //             3 out of line
  EXPECT_EQ(message.inline_struct.l0_inline.l1_inline.l2_present->l3_present->handle_3,
            dummy_handle_1);
  //             3 inline
  EXPECT_EQ(message.inline_struct.l0_inline.l1_inline.l2_present->l3_inline.handle_3,
            dummy_handle_2);
  //             handle
  EXPECT_EQ(message.inline_struct.l0_inline.l1_inline.l2_present->handle_2, dummy_handle_3);
  //         2 inline
  //             3 out of line
  EXPECT_EQ(message.inline_struct.l0_inline.l1_inline.l2_inline.l3_present->handle_3,
            dummy_handle_4);
  //             3 inline
  EXPECT_EQ(message.inline_struct.l0_inline.l1_inline.l2_inline.l3_inline.handle_3, dummy_handle_5);
  //             handle
  EXPECT_EQ(message.inline_struct.l0_inline.l1_inline.l2_inline.handle_2, dummy_handle_6);
  //     handle
  EXPECT_EQ(message.inline_struct.l0_inline.handle_0, dummy_handle_7);
  //     1 out of line
  //         handle
  EXPECT_EQ(message.inline_struct.l0_inline.l1_present->handle_1, dummy_handle_8);
  //         2 out of line
  //             3 out of line
  EXPECT_EQ(message.inline_struct.l0_inline.l1_present->l2_present->l3_present->handle_3,
            dummy_handle_9);
  //             3 inline
  EXPECT_EQ(message.inline_struct.l0_inline.l1_present->l2_present->l3_inline.handle_3,
            dummy_handle_10);
  //             handle
  EXPECT_EQ(message.inline_struct.l0_inline.l1_present->l2_present->handle_2, dummy_handle_11);
  //         2 inline
  //             3 out of line
  EXPECT_EQ(message.inline_struct.l0_inline.l1_present->l2_inline.l3_present->handle_3,
            dummy_handle_12);
  //             3 inline
  EXPECT_EQ(message.inline_struct.l0_inline.l1_present->l2_inline.l3_inline.handle_3,
            dummy_handle_13);
  //             handle
  EXPECT_EQ(message.inline_struct.l0_inline.l1_present->l2_inline.handle_2, dummy_handle_14);
  // 0 out of line
  //     1 inline
  //         handle
  EXPECT_EQ(message.inline_struct.l0_present->l1_inline.handle_1, dummy_handle_15);
  //         2 out of line
  //             3 out of line
  EXPECT_EQ(message.inline_struct.l0_present->l1_inline.l2_present->l3_present->handle_3,
            dummy_handle_16);
  //             3 inline
  EXPECT_EQ(message.inline_struct.l0_present->l1_inline.l2_present->l3_inline.handle_3,
            dummy_handle_17);
  //             handle
  EXPECT_EQ(message.inline_struct.l0_present->l1_inline.l2_present->handle_2, dummy_handle_18);
  //         2 inline
  //             3 out of line
  EXPECT_EQ(message.inline_struct.l0_present->l1_inline.l2_inline.l3_present->handle_3,
            dummy_handle_19);
  //             3 inline
  EXPECT_EQ(message.inline_struct.l0_present->l1_inline.l2_inline.l3_inline.handle_3,
            dummy_handle_20);
  //             handle
  EXPECT_EQ(message.inline_struct.l0_present->l1_inline.l2_inline.handle_2, dummy_handle_21);
  //     handle
  EXPECT_EQ(message.inline_struct.l0_present->handle_0, dummy_handle_22);
  //     1 out of line
  //         handle
  EXPECT_EQ(message.inline_struct.l0_present->l1_present->handle_1, dummy_handle_23);
  //         2 out of line
  //             3 out of line
  EXPECT_EQ(message.inline_struct.l0_present->l1_present->l2_present->l3_present->handle_3,
            dummy_handle_24);
  //             3 inline
  EXPECT_EQ(message.inline_struct.l0_present->l1_present->l2_present->l3_inline.handle_3,
            dummy_handle_25);
  //             handle
  EXPECT_EQ(message.inline_struct.l0_present->l1_present->l2_present->handle_2, dummy_handle_26);
  //         2 inline
  //             3 out of line
  EXPECT_EQ(message.inline_struct.l0_present->l1_present->l2_inline.l3_present->handle_3,
            dummy_handle_27);
  //             3 inline
  EXPECT_EQ(message.inline_struct.l0_present->l1_present->l2_inline.l3_inline.handle_3,
            dummy_handle_28);
  //             handle
  EXPECT_EQ(message.inline_struct.l0_present->l1_present->l2_inline.handle_2, dummy_handle_29);

  // Finally, check that all absent members are nullptr.
  EXPECT_NULL(message.inline_struct.l0_absent);
  EXPECT_NULL(message.inline_struct.l0_inline.l1_absent);
  EXPECT_NULL(message.inline_struct.l0_inline.l1_inline.l2_absent);
  EXPECT_NULL(message.inline_struct.l0_inline.l1_inline.l2_inline.l3_absent);
  EXPECT_NULL(message.inline_struct.l0_inline.l1_inline.l2_present->l3_absent);
  EXPECT_NULL(message.inline_struct.l0_inline.l1_present->l2_absent);
  EXPECT_NULL(message.inline_struct.l0_inline.l1_present->l2_inline.l3_absent);
  EXPECT_NULL(message.inline_struct.l0_inline.l1_present->l2_present->l3_absent);
  EXPECT_NULL(message.inline_struct.l0_present->l1_absent);
  EXPECT_NULL(message.inline_struct.l0_present->l1_inline.l2_absent);
  EXPECT_NULL(message.inline_struct.l0_present->l1_inline.l2_inline.l3_absent);
  EXPECT_NULL(message.inline_struct.l0_present->l1_inline.l2_present->l3_absent);
  EXPECT_NULL(message.inline_struct.l0_present->l1_present->l2_absent);
  EXPECT_NULL(message.inline_struct.l0_present->l1_present->l2_inline.l3_absent);
  EXPECT_NULL(message.inline_struct.l0_present->l1_present->l2_present->l3_absent);
}

TEST(UnknownEnvelope, NumUnknownHandlesExceedsUnknownArraySize) {
  uint8_t bytes[] = {
      2,   0,   0,   0,   0,   0,   0,   0,    // max ordinal
      255, 255, 255, 255, 255, 255, 255, 255,  // alloc present

      0,   0,   0,   0,   0,   0,   0,   0,  // envelope 1: num bytes / num handles
      0,   0,   0,   0,   0,   0,   0,   0,  // alloc present

      0,   0,   0,   0,   65,  0,   0,   0,    // envelope 1: num bytes / num handles
      255, 255, 255, 255, 255, 255, 255, 255,  // alloc present
  };

  const char* error = nullptr;
  auto status = fidl_decode(&llcpp::fidl::test::coding::fidl_test_coding_SimpleTableTable, bytes,
                            ArrayCount(bytes), nullptr, 0, &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_STR_EQ(error, "number of unknown handles exceeds unknown handle array size");
}

// Most fidl_encode_etc code paths are covered by the fidl_encode tests.
// The FidlDecodeEtc tests cover additional paths.

TEST(FidlDecodeEtc, decode_invalid_handle_info) {
  nonnullable_handle_message_layout message = {};
  message.inline_struct.handle = FIDL_HANDLE_PRESENT;

  zx_handle_info_t handle_infos[] = {{
      .handle = ZX_HANDLE_INVALID,
      .type = ZX_OBJ_TYPE_NONE,
      .rights = 0,
      .unused = 0,
  }};

  const char* error = nullptr;
  auto status = fidl_decode_etc(&nonnullable_handle_message_type, &message, sizeof(message),
                                handle_infos, ArrayCount(handle_infos), &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  EXPECT_NOT_NULL(error);
  const char expected_error_msg[] = "invalid handle detected in handle table";
  EXPECT_STR_EQ(expected_error_msg, error, "wrong error msg");
}

TEST(FidlDecodeEtc, decode_single_present_handle_info_handle_rights_subtype_match) {
  nonnullable_handle_message_layout message = {};
  message.inline_struct.handle = FIDL_HANDLE_PRESENT;

  zx_handle_info_t handle_infos[] = {{
      .handle = dummy_handle_0,
      .type = ZX_OBJ_TYPE_CHANNEL,
      .rights = ZX_RIGHT_READ | ZX_RIGHT_WRITE,
      .unused = 0,
  }};

  const char* error = nullptr;
  auto status = fidl_decode_etc(&nonnullable_channel_message_type, &message, sizeof(message),
                                handle_infos, ArrayCount(handle_infos), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.handle, dummy_handle_0);
}

TEST(FidlDecodeEtc, decode_single_present_handle_info_no_subtype_same_rights) {
  nonnullable_handle_message_layout message = {};
  message.inline_struct.handle = FIDL_HANDLE_PRESENT;

  zx_handle_info_t handle_infos[] = {{
      .handle = dummy_handle_0,
      .type = ZX_OBJ_TYPE_CHANNEL,
      .rights = ZX_RIGHT_READ | ZX_RIGHT_WRITE,
      .unused = 0,
  }};

  const char* error = nullptr;
  auto status = fidl_decode_etc(&nonnullable_handle_message_type, &message, sizeof(message),
                                handle_infos, ArrayCount(handle_infos), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  EXPECT_EQ(message.inline_struct.handle, dummy_handle_0);
}

TEST(FidlDecodeEtc, decode_single_present_handle_info_handle_rights_wrong_subtype) {
  nonnullable_handle_message_layout message = {};
  message.inline_struct.handle = FIDL_HANDLE_PRESENT;

  zx_handle_info_t handle_infos[] = {{
      .handle = dummy_handle_0,
      .type = ZX_OBJ_TYPE_VMO,
      .rights = ZX_RIGHT_READ | ZX_RIGHT_WRITE,
      .unused = 0,
  }};

  const char* error = nullptr;
  auto status = fidl_decode_etc(&nonnullable_channel_message_type, &message, sizeof(message),
                                handle_infos, ArrayCount(handle_infos), &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  ASSERT_SUBSTR(error, "decoded handle object type does not match expected type");
}

TEST(FidlDecodeEtc, decode_single_present_handle_info_handle_rights_missing_required_rights) {
  nonnullable_handle_message_layout message = {};
  message.inline_struct.handle = FIDL_HANDLE_PRESENT;

  zx_handle_info_t handle_infos[] = {{
      .handle = dummy_handle_0,
      .type = ZX_OBJ_TYPE_CHANNEL,
      .rights = ZX_RIGHT_READ,
      .unused = 0,
  }};

  const char* error = nullptr;
  auto status = fidl_decode_etc(&nonnullable_channel_message_type, &message, sizeof(message),
                                handle_infos, ArrayCount(handle_infos), &error);

  EXPECT_EQ(status, ZX_ERR_INVALID_ARGS);
  ASSERT_SUBSTR(error, "required rights");
}

// Disabled on host due to syscall.
#ifdef __Fuchsia__
TEST(FidlDecodeEtc, decode_single_present_handle_info_handle_rights_too_many_rights) {
  nonnullable_handle_message_layout message = {};
  message.inline_struct.handle = FIDL_HANDLE_PRESENT;

  zx_handle_t h0, h1;
  auto status = zx_channel_create(0, &h0, &h1);
  ASSERT_EQ(status, ZX_OK);

  zx_handle_info_t handle_infos[] = {{
      .handle = h0,
      .type = ZX_OBJ_TYPE_CHANNEL,
      .rights = ZX_RIGHT_READ | ZX_RIGHT_WRITE | ZX_RIGHT_TRANSFER,
      .unused = 0,
  }};

  const char* error = nullptr;
  status = fidl_decode_etc(&nonnullable_channel_message_type, &message, sizeof(message),
                           handle_infos, ArrayCount(handle_infos), &error);

  EXPECT_EQ(status, ZX_OK);
  EXPECT_NULL(error, "%s", error);
  // There should be a new handle created by zx_handle_replace.
  EXPECT_NE(message.inline_struct.handle, h0);

  zx_info_handle_basic_t info;
  zx_object_get_info(message.inline_struct.handle, ZX_INFO_HANDLE_BASIC, &info, sizeof(info),
                     nullptr, nullptr);
  EXPECT_EQ(info.type, handle_infos[0].type);
  EXPECT_EQ(info.rights, ZX_RIGHT_READ | ZX_RIGHT_WRITE);
}
#endif

}  // namespace
}  // namespace fidl